Time
by mundane-pansycakes
Summary: Simon and Isabelle have had a steady relationship for a while now. But what happens when the topic of immortality is brought up? Sizzy one-shot


**Here's my Sizzy one-shot. Hope you guys like it! **

Simon sat on the edge of his bed, tapping his leg impatiently. It was a mundane habit of his, something he did to feel normal. Although he drank this morning, he couldn't help but feel painfully hungry. But not for blood. For her.

Isabelle walked into the room seconds later, smiling at him as she shut the door. She was dressed in her typical style: a short black dress, fishnets, and long, lace-up boots. Her endless hair was swept up into a messy ponytail, her glimmering whip wrapped around her arm. She was stunningly beautiful, as always, to Simon, making his throat dry at the sight of her.

"Hey, Simon," she grinned, leaning over to kiss him gently on the mouth before sitting beside him. The warm, vanilla scent of her skin made Simon feel even more vulnerable. All he wanted was to be close to her, to feel her body against his, to have their lips meeting. But now wasn't the time.

"Hey, Iz," he said, almost stuttering. What am I doing? he thought to himself. Get it together.

She yawned and tossed her hair back, still unaware of his weird behavior. "My mom and dad have been fighting all day. More Clave business. It's made me exhausted, so I'm glad I get to escape to you," she smiled mischievously, leaning in closer to Simon. He could smell the blood flowing freely through her, the tempting scent of salt on her skin as her nose touched his. She kissed him softly, her fingers tracing his jaw line. He tilted his head upwards, slinking his arms around her in anticipation. He reached up and tugged at her ponytail until her hair fell loose, tumbling down onto her shoulders, a cascading wave of blackness. She started to pull at his shirt when Simon abruptly pulled away, unable to do this without talking first.

"Isabelle, wait—I need to talk to you," he murmured, looking into her shining eyes. She bit her lip, then sank back against the bed, obviously disappointed. "I'm sorry, but I need to get this out." He took a deep, unnecessary breath. "I'm—I'm scared, Izzy."

"Of what? You know I won't let anything happen to you, Simon," she assured him, taking his hand.

"I'm scared of this," he admitted, looking down at their hands, locked together. Her small, scarred fingers wrapped in his strong, smooth ones. A look of horror passed over Isabelle's face, terrified of the reasoning behind his words. "No—no, not like that. I love this. I love everything about it, everything about you. But I'm terrified of what the future holds."

"What do you mean? You don't think this will last?" she gasped, fighting back tears. She took a large breath, trying to gather herself together as Simon rapidly shook his head, wishing to calm her.

"No, Izzy, no. Please just listen to me!" he nearly yelled, begging to stop her pain. He couldn't stand it when she was hurting, especially not when he was caused it. The look she got on her face, her mouth twisting downwards, her eyes squeezing shut. He couldn't bare it. "I know that this will last. I know it in every single piece of me, every bone, every vein. I love you Isabelle—that will never change. But, you will. You're almost eighteen, Iz. And I'm still sixteen. Right now it doesn't seem like a lot, but what about in five years? Ten?" he whispers, the fear in her eyes plain as day. He remembered vaguely what Camille said to him, so long ago. She had told him that this would never work, that clinging to his mortal friends would be impossible for him. She was right.

"It won't matter, Simon! It won't!" she screamed frantically, grabbing at his shirt, drawing him closer. "I don't care about any of that. I care about you!"

"Iz, please. Let me talk," he whispered in a calm, soothing voice. She quieted down and stared back up at him, piercing her lip with her teeth to keep quiet. "I know it won't matter to you. And it would never matter to me. I would love you at any age, at any time. But it's not just us in this situation, Iz. The whole world is around us. We could never truly be together in public. Sure, when you're 30 or something we could go out; but we could never hold hands, never kiss. We'd have to restrain ourselves at every waking minute, contain every desire until we were alone. I would do it for you, Iz. I would do it for a thousand years if it meant being with you every minute. But I can't put you through that kind of pain," his voices cracked, straining to get the words out without breaking down. He needed to stay strong for her.

"I know we still have time. Four years, maybe more if we're lucky. But I don't think we should continue if we're going to have to stop. I don't want to get too attached—for—," he broke off, unable to say His name. "—for crying out loud, I'm already madly in love with you! I don't know how I'll ever stop. But I do know that if you keep holding on to me, I'll just hurt you even more in the end. You deserve someone you can grow old with, Iz. A Shadowhunter as good as you. Not some monstrous Downworlder—"

"Don't you ever call yourself that, Simon Lewis," she interrupted, regaining herself for the moment. "You're not like that. You're so much more than that." She leaned in again, pulling his face closer to his.

"Stop," Simon murmured, pushing away. "I can't hurt you like this."

"You're not hurting me. You're doing everything but hurting me."

"That's what you think now. But when every day is a fight to keep our secret, you won't be thinking that anymore. You'll be regretting ever meeting me, ever—" She pulled him against herself, grabbing wildly at his hair. Their lips collided in a rage of passion and intensity. All of Simon's reasoning went away as she slipped her hands under his shirt, ripping it off of him. His rationality disappeared with every hot breath against his skin, with every sizzling touch of her fingertips against his bare chest.

Simon didn't even realize it when Isabelle's dress was thrown onto the floor, didn't even notice that his hands were the ones doing the throwing. He couldn't think; he could only do. He moved his lips away from her mouth, and instead trailed kisses down her neck, across her shoulders, all while she kicked her boots and fishnets away eagerly. He could smell the indescribable scent of blood, the tempting sweetness calling to him. But he didn't even care. All he wanted was Isabelle.

"Who care's about the future," he breathed while she tore his pants away. Her mouth was just inches away from his, her eyes glittering with desire. "We have right now."


End file.
